The primary objective of the study is to test the incremental efficacy and outcomes of an aftercare program of Cognitive Behavioral Therapy combined with motivational therapy (CBT-MT) relative to treatment as usual (TAU) in improving depression, substance use, and healthcare outcomes in a population with drug dependence and comorbid major depressive disorder (MDD). The investigators expect that among drug-dependent patients with comorbid MDD, CBT-MT will yield better clinical outcomes relative to TAU in reducing depressive symptoms and substance use and improving healthcare outcomes during treatment.